MAPPING OF PROVISIONAL QUANTITATIVE TRAIT LOCI INFLUENCING TEMPORAL VARIATION IN LOCOMOTOR-ACTIVITY IN THE LS X SS RECOMBINANT INBRED STRAINS

The finding that stress-induced locomotor activity exhibited a signifi cant strain x time interaction in the LS x SS RI strains prompted exam ination of QTL influencing this behavior as a function of time. The de gree of genetic determination for locomotor activity was 0.26 for the first 5 min and decreased to 0.16 for the last 5 min of a 30-min test but the number of genetic factors stayed relatively constant (three or four) across time. A QTL point analysis revealed a total of 15 QTL, 5 -8 per 5-min time block. Few of the QTL were detected across all time points and different combinations of QTL were evident for each time pe riod. Five of the QTL were in common with those reported by other inve stigators for similar behaviors. The results suggest that locomotor be havior is under a greater degree of genetic control during the initial part of the test but environmental factors become increasingly import ant as the test progresses. Furthermore, different genetic factors app ear to be mediating genetic variation in locomotor behavior at any giv en time point.